The advent and explosion of the World Wide Web and the Internet have created a huge demand for data communications bandwidth. Once satisfied with a 56 Kb/s analog modem, many home users are now demanding broadband Internet connections capable of sustaining 1.5 MB/S, or more. In order to satisfy this ever-increasing demand for bandwidth to the home and office, several competing standards for data communications have emerged. One of these standards is digital subscriber line (“DSL”) technology.
DSL is a high-speed connection that utilizes the same wires as a regular telephone line. DSL offers a number of advantages over other types of high-speed links to the home and office. For instance, because DSL utilizes a higher frequency for data communications than that used for voice communications, the same phone line may be used for both data and voice simultaneously. Moreover, several different types of DSL connections exist that can provide extremely high data rates without requiring new wiring. Therefore, DSL can operate on the existing phone line already present in most homes and businesses. Additionally, other types of broadband connections to the home such as cable modems, utilize a shared network group for a number of subscribers. Adding users to such a shared network means lower performance in many instances. Because DSL provides a dedicated connection from each user back to the nearest central office (“CO”), users typically do not see a performance decrease as new users are added.
A typical DSL installation utilizes two pieces of equipment. A transceiver, or modem, is located at the customer end, and a DSL access multiplexer (“DSLAM”) is located at the CO serving the customer. The DSL transceiver located at the customer location connects to a customer's data processing equipment and to the standard telephone line connection located at the customer premises. The DSLAM, located at the central office serving the customer is also connected to the telephone line that the DSL transceiver is connected to. The DSLAM communicates with the DSL transceiver and provides data communication between the central office and the customer premises according to the particular DSL standard implemented. A typical DSLAM takes such connections from many customers and aggregates them onto a single high-capacity connection to the Internet or other type of network. A data switch, such as an asynchronous transfer mode (“ATM) switch is typically utilized to interface the DSLAM to the Internet or other type of data communications network. In some installations, a single data switch may serve multiple DSLAMs.
In some installations, one DSLAM may serve thousands of DSL customers. When the number of customers served by a particular DSLAM approaches the maximum number, it is necessary to “rehome” the DSLAM to another data switch, or to another port on the data switch currently serving the DSLAM. Alternately if the data connection between the data switch serving the DSLAM has become saturated, it may be necessary to upgrade this connection. In order to do so, it is likewise necessary to rehome the DSLAM to another data switch or to another port supporting a faster connection.
Although previous methods exist for rehoming the DSLAM between a data switch or a port on a data switch, these previous methods suffer from a number of serious drawbacks. The first such drawback is the customer data communication outage that occurs when the DSLAM servicing the customer is moved to a new data switch or port. Previous methods for rehoming a DSLAM between data switches or ports on a data switch cause long periods of downtime for DSL customers. Because providing DSL service is a highly competitive business, such downtime may result in the unacceptable loss of customers. At a minimum, such downtime can result in unhappy customers and a reduced network availability metric.
Another drawback with previous methods for rehoming a DSLAM between a data switch, or a port on a data switch, occurs when DSL service is resold to a network service provider (“NSP”). In such a scenario, a permanent virtual circuit (“PVC”) is established between the data switch servicing the DSLAM and the NSP. The NSP then resells the DSL service to the end customer. In such a scenario, it is necessary to gain the cooperation of the NSP servicing the customer prior to rehoming the DSLAM. Moreover, coordination is required with the NSP when the DSLAM is rehomed in order to ensure that the downtime experienced by the end-user is minimized. However, it is frequently not possible to obtain the cooperation of the NSP or, even if the cooperation is obtained, it is often difficult to coordinate with the NSP in such a way that minimizes user downtime.